String Gauge

String gauge is a confusing subject for a number of reasons mainly down to a lack of a single standard adhered to by all:

Americans and Europeans decided on different scalesIncreasing gauge numbers on the US scale indicate thinner string while increasing gauge numbers in Europe indicate thicker stringThe boundaries between the gauge numbers are differently defined by different string manufacturersSome manufaturers use intermediate gauge sizes (on some of the gauges only) which they label L (light) but some label these M (micro)The boundaries of the gauge numbers overlap so strings of some diameters sit in 2 gauges.

The best comparator for string gauge is thus the strung diameter. The chart below shows the gauges, diameters and their suitability to the different racquet sports. Cells shaded grey suggest the string gauge is normally regarded suitable for the sport. Cells shaded red suggest the string gauge is getting extreme for the sport.

Thicker string will be more durable. Thinner string will improve power - Provided it is not pushed past its elastic limit. Thinner string will stretch more than thicker string under the same load and thus have a greater "trampoline effect". Thinner string will stretch more for the same load and thus give less control.Thinner string will improve feel. Not only does it stretch more but it will cut into the surface of the ball more than thicker string which provides better grip and ability to impart spin.String manufacturers will claim thinner string will present the benefits of less air resistance and will be lighter in the racquet head. Both factors are likely to be negligible to even the best players.